Melatonin decrease the oxidative stress produced by 2,4-dichlorophenoxyacetic acid

BONGIOVANNI BETTINA; DE LORENZI PAOLA; FERRI ALEJANDRO; KONJUH CINTIA; RASSETTO MAURICIO; EVANGELISTA DE DUFFARD ANA MARIA; CARDINALI DANIEL; DUFFARD RICARDO

Pinamar

Congreso; X Congress of the Panamerican Association for Biochemistry and Molecular Biology (PABMB) the XLI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB) and the XX Annual Meeting of the Argentine Society for Neurochemistry; 2005

anamerican Association for Biochemistry and Molecular Biology (PABMB)

2,4-Dichlorophoxyacetic (2,4-D) acid and derivatives are herbicides widely used in Argentine and other of the world. Exposure to 2,4-D, its ester and salt formulations, have been associated with a range of adverse health effects in humans and different animal species, from embryotoxicity and teratogenicity to neurotoxicity. In previous work of our laboratory, it has been demonstrated that after 24 and 48 hs of treatment with 2,4-D there is an induction of apoptosis in rat cerebellar granule cell cultures, a process generally believed to be mediated by oxidative stress. Furthermore, culture rat cerebellar granule cells are glutamatergic neurons, which express all of the glutamate receptor subtypes and have been used as a model to study excitotoxicity caused by neurotoxins. Giusti et al.  found melatonin to be protective against the toxic action of Kainic acid on non-NMDA receptor. However, did not definitively establish melatonin as a true radical scavenger. At the present time, we demonstrated that of toxicity mechanism for this herbicide involve the oxidative stress for this, we decided to study melatonin as protective drugs.The aim of the present work was to determinate in rat cerebellar granule cell cultures, exposed to 2,4-D (1mM) and/or Melatonin (0.1, 0.5 and 1 mM) for 48 hs, cell viability for MTT method, reactive oxygen species (ROS) using a fluorescent compound (DCF), catalase (CAT) activity by method described by Beers and Sizer and both Mn- and Cu, Zn-superoxide dismutase (SOD) activity by the method of Fridovich. We observed that the 0.1 mM and 0.5 mM Melatonin produced to increase the viability cell (256 ± 8 and 120 ± 8 respectively), while that 1 mM Melatonin reduced the viability with respect control group (101 ± 1). On the other hand, we compared these viability with the 2,4-D group (72 ± 1) and we observed that the treatment with 0.1 mM Melatonin/1 mM 2,4-D presented higher viability (87 ± 2) than the herbicide alone. However, did not occur with others dose. Furthermore, we founded higher ROS levels with 0.5 and 1mM Melatonin and lower levels with 0.1 mM Melatonin than the control group, while that the treatment with both drugs (0.1mM Melatonin/1mM 2,4-D) showed lower levels than the 2,4-D alone. The CAT activity was higher when we compared the same group. In conclusion, these facts would be important as mechanism of protection against the herbicide.